Foreign RFID tag discrimination and management

ABSTRACT

Managing foreign RFID tags within a secured area involves use of a first RFID portal system to read tag data from an RFID tag present within a first portal zone. A processing device associated with the first RFID portal system is used to determine whether the RFID tag is entering the secured area. The determination is based on an evaluation of a direction of travel of the RFID tag through the first portal zone. Responsive to determining that the RFID tag is in fact entering the secured area, one or more operations are performed to cause a first tag value corresponding to the tag data to be added into a safe to exit (STE) list.

CLAIM OF PRIORITY

This application is a Continuation Application of U.S. patentapplication Ser. No. 16/135,988 filed Sep. 19, 2018, entitled: “FOREIGNRFID TAG DISCRIMINATION AND MANAGEMENT”, the entire contents of whichare hereby incorporated by reference.

BACKGROUND Statement of the Technical Field

The technical field of this disclosure concerns RFID systems, and moreparticularly RFID portals which process RFID tags at an entrance to asecured facility.

Description of the Related Art

An RFID portal is a system which is used for tracking items passingthrough doorways, hallways or corridors. Conventional RFID portalsidentify the direction of RFID tags crossing a portal transition definedby a choke point through which items must pass when they move from onedefined area to a second defined area. In many implementations, an RFIDportal determines tag directionality, which refers to a direction thetag is moving through the choke point. A common purpose for determiningtag directionality is to discriminate between those tags which areattached to items which are entering a secured facility as compared tothose tags which are attached to items that are leaving the securedfacility.

In some systems, tag directionality is determined by the order in whichtags are read. For example, a tag read by a first antenna and then by asecond antenna spaced a distance apart from the first antenna, is likelymoving from the first to second antenna. More advanced systems can alsouse beam steerable antennas to detect the presence of RFID tags indifferent locations as they move through a portal zone. One example of asystem for determining tag directionality is disclosed in U.S. Pat. No.9,519,811 to Simon, et al.

A number of organizations have set standards for RFID tags. One type ofRFID tag for which a standard has been established is known as anEPCglobal UHF Class 1 Generation 2 (hereinafter “EPC Gen2”) type tags.These tags have certain well known characteristics.

SUMMARY

This document concerns a method and system for managing foreign RFIDtags within a secured area. In a method disclosed herein, a first RFIDportal system is used to read tag data from an RFID tag present within afirst portal zone. At least one processing device associated with thefirst RFID portal system is used to determine whether the RFID tag isentering the secured area. According to one aspect, the determinationcan be based on an evaluation of a direction of travel of the RFID tagthrough the first portal zone. Responsive to a determination that theRFID tag is in fact entering the secured area, one or more operationsare performed to cause a first tag value corresponding to the tag datato be added into a safe to exit (STE) list. This STE list can bemaintained in an electronic data storage device accessible to the atleast one processing device, and specifies one or more RFID tags whichare permitted to leave the secured area without triggering an alarm.

Thereafter, a second RFID portal system is used to read a departing tagdata from a departing RFID tag that is exiting the secured premises. Thesecond RFID portal system is selectively prevented from generating analert if a second tag value associated with the departing tag datamatches at least one tag value stored in the STE list. In somescenarios, the second RFID portal system can be the first RFID portalsystem, but in other scenarios the second RFID portal system can bedistinct from the first RFID portal.

According to one aspect, the first tag value is advantageouslycommunicated to a central server in communication with the first andsecond RFID portal systems. According to another aspect, the first tagvalue is communicated to at least the second RFID portal system.Accordingly, the STE list can be advantageously maintained at both thefirst and second RFID portal systems. The first tag value can beselectively removed from the STE list responsive to at least one manualuser control or intervention operation. Further the first tag value canbe automatically selectively removed from the STE list after apredetermined duration of time.

According to another aspect, the first tag value can be automaticallyselectively prevented from being added to the STE list when the at leastone processing device determines that the first RFID tag has entered thesecured area concurrent with a predetermined number of other RFID tags.In some scenarios, the method can involve automatically selectivelypreventing the addition to the STE list of one or more of the tag valuesduring at least one predetermined period of time.

The solution also concerns an RFID portal system for managing foreignRFID tags within a secured area. The system includes a first RFID portalcomprising a first RFID reader which has an associated control unit. Thecontrol unit is configured to generate one or more commands to cause thefirst RFID reader to read tag data from an RFID tag present within afirst portal zone and determine, based on an evaluation of a directionof travel of the RFID tag through the first portal zone, whether theRFID tag is entering the secured area. In response to a determinationthat the RFID tag is entering the secured area, the control unit willperform at least one operation to cause a first tag value correspondingto the tag data to be added into a safe to exit (STE) list maintained inat least one electronic data storage device. The STE list specifies oneor more RFID tags which are permitted to leave the secured area withouttriggering an alarm.

The RFID portal system can also include a second RFID portal similar tothe first RFID portal system. The second RFID reader can include asecond control unit configured to generate one or more commands. Thesecommands can cause the second RFID reader to read a departing tag datafrom a departing RFID tag that is exiting the secured premises, andselectively prevent the second system controller from generating analert if a second tag value associated with the departing tag datamatches at least one tag value in the STE list. In some scenarios, thesecond RFID portal system is the first RFID portal system. In otherscenarios the second RFID portal system can be distinct from the firstRFID portal system.

The system can further include a central server which is configured tofacilitate distribution of information concerning the content of the STElist, from the first RFID portal system to at least the second RFIDportal system. Alternatively, the first RFID reader can be configured todirectly communicate the first tag value to at least the second RFIDreader for updating an STE list. Notably, each of the first and secondRFID reader is configured to maintain a local copy of the STE list in afirst and second local data storage device.

In the RFID portal system described herein, one or more of the RFIDreaders can be configured to selectively remove the first tag value fromthe STE list responsive to at least one manual user control operation.In some solutions presented herein, the one or more RFID readers areconfigured to selectively remove the first tag value from the STE listafter a predetermined duration of time. Further, the first RFID readercan be configured to automatically selectively prevent the first tagvalue from being added to the STE list upon a determination that thefirst RFID tag has entered the secured area concurrent with apredetermined number of other RFID tags. The first RFID reader can alsobe configured to automatically selectively prevent the addition to theSTE list of one or more of the tag values during at least onepredetermined period of time.

BRIEF DESCRIPTION OF THE DRAWINGS

This disclosure is facilitated by reference to the following drawingfigures, in which like numerals represent like items throughout thefigures, and in which:

FIG. 1 is a plan view of an RFID portal system at a choke point.

FIG. 2 is a top view of the RFID portal system in FIG. 1 .

FIG. 3 is a drawing that is useful for understanding the concept of aportal zone surrounding the RFID portal system in FIG. 1 .

FIG. 4 is a diagram that is useful for understanding how a plurality ofRFID portal systems shown in FIGS. 1-3 can be integrated into chokepoints around a secured facility.

FIG. 5 is a drawing that is useful for understanding a communicationsarrangement among a plurality of RFID portal systems.

FIGS. 6A-6B are a set of flowcharts that are useful for understanding aforeign RFID tag management system.

FIG. 7 is a drawing that is useful for understanding a safe to exit(“STE”) list.

FIG. 8A is a block diagram that is useful for understanding a RFIDportal system controller.

FIG. 8B is a block diagram that is useful for understanding an RFIDreader with integrated control unit.

FIG. 9 is a block diagram that is useful to facilitate an understandingof a handheld RFID tag reader.

FIG. 10 is a block diagram that is useful to facilitate an understandingof an RFID system server.

DETAILED DESCRIPTION

It will be readily understood that the solution described herein andillustrated in the appended figures could involve a wide variety ofdifferent configurations. Thus, the following more detailed description,as represented in the figures, is not intended to limit the scope of thepresent disclosure, but is merely representative of certainimplementations in various different scenarios. While the variousaspects are presented in the drawings, the drawings are not necessarilydrawn to scale unless specifically indicated.

The solution concerns a method and system for managing foreign RFID tagswithin a secured area. For purposes of this disclosure, a foreign RFIDtag can be understood to be any RFID tag which enters a RFID securedarea through a choke point that is monitored by an RFID portal. Forexample, consider a scenario in which the secured area is a retail storelocation. A foreign RFID tag may be one that is attached to merchandisethat a customer has previously purchased at another retail store. Sincethe merchandise was already purchased at a different store, it would beundesirable for the RFID tag to trigger an alarm when it is subsequentlydetected leaving the secured location.

One way to prevent such alarms could involve restricting the RFID portalso that it will automatically filter out (i.e. prevent alarms) for RFIDtags having specific tag data and/or tag header data. However, thisapproach is not scalable for large retail facilities which utilizesource tagging methods. Another approach could involve comparing tagread data from detected RFID tags to a database specifying dataexclusively associated with those tags which will trigger an alarm. Forexample, this approach could involve a list of specific ElectronicProduct Codes (EPCs) associated with RFID tags which will trigger analarm. However, this approach does not adequately address all potentialuse cases, such as those involving merchandise returns.

A solution to the foregoing problem can involve using an RFID portalsystem to read tag data from an RFID tag present within a portal zone.At least one processing device associated with the RFID portal system isused to determine whether the RFID tag is entering the secured area. Forexample, this determination can be based on an evaluation of a directionof travel of the RFID tag through the portal zone. In response to adetermination that the RFID tag is entering the secured area, theprocessing device will cause a first tag value corresponding to the tagdata, to be added into a safe to exit (STE) list. The STE list specifiesone or more RFID tags which are permitted to leave the secured areawithout triggering an alarm. The STE list is maintained in an electronicdata storage device accessible to the processing device. In somescenarios, the tag value can be the same as the tag data, but this isnot a requirement and in some instances the tag value can be derivedfrom all or part of the tag data.

Thereafter, a second RFID portal system may read tag data from adeparting RFID tag that is departing or exiting the secured premises. Adeparting RFID tag has the potential to trigger an alarm when it isdetermined that the tag is exiting the secured premises. To prevent suchan alarm, the second RFID portal system will automatically inhibit analert if a tag value associated with the departing tag data matches atleast one tag value stored in the STE list. In some scenarios the firstand second RFID portal system can be the same portal system. However,the solution is not limited in this respect. In other scenarios (e.g.,where a secured area includes two or more entrances and exits), thesecond RFID portal system can be distinct from the first RFID portalsystem. In such a scenario, the second RFID portal may be associatedwith a second portal zone of the secured area that is distinct from thefirst portal zone. When a particular secured area includes multipleentrances and exits, there could of course be numerous distinct RFIDportal systems, each associated with a different entrance or exit.

In FIGS. 1-3 there is shown an RFID portal system 100 which is usefulfor understanding certain aspects of a solution for managing foreignRFID tags in a secure environment. The RFID portal system includes twoRFID readers 106 a, 106 b and each of them are respectively attached toantennas 102 a, 102 b mounted on sides of the portal. RFID readers arewell known in the art and therefore will not be described here indetail. However, it should be understood that an RFID reader asreferenced herein will be capable of generating RFID tag exciter signalsto control and elicit responses from one or more of a plurality of RFIDtags in a RFID portal zone. The RFID exciter signals can also serve as asource of power for energizing the RFID tags.

The exciter signals generated by the RFID reader and responses receivedby the reader will be in accordance with an RFID system standard that isnow known or known in the future. The RFID tag reader will also becapable of detecting, identifying and/or processing one or more theresponses from the plurality of RFID tags in a portal zone. In somescenarios, certain control functions of the RFID reader can be handledby a system controller 108. In such scenarios, the RFID readers caninclude suitable interface circuitry to facilitate communications with asystem controller 108 as described below. For example, the interfacecircuitry can facilitate communication of information regarding detectedresponses received from RFID tags. Such interface circuitry can alsofacilitate reception of interrogation commands and/or antenna beamcontrol commands from the system controller.

In the arrangement shown, the antennas are mounted on pedestals 103 a,103 b, but the solution is not limited in this regard. The antennascould be mounted in the ceiling, on a wall, or in the ground, and themethod described herein would still be applicable. There is norestriction regarding the type of antennas which are used to produce therequired field patterns. Each of the antennas 102 a, 102 b can becomprised of one or more antenna elements. In some scenarios, the one ormore individual antenna elements can be comprised of planar antennaelements which may be disposed on a suitable dielectric substrate. Oneexample of such a planar antenna element includes a patch antenna. Patchantennas are well known and therefore will not be described in detail.However, it should be understood that the one or more patch antennaelements can be used to achieve a particular set of beam patterns thatis required for a particular application. For example, the patchantennas can be configured to operate independently or in a phased arrayconfiguration to produce one or more desired beam patterns. The varioustypes of antenna beam forming methods are beyond the scope of thisdisclosure and therefore will not be described in detail. However in onepossible scenario, each antenna 102 a, 102 b may be comprised of two (2)or in some cases four (4) patch antennas which are housed inside of eachpedestal 103 a, 103 b.

In the example shown, the antennas 102 a, 102 b are understood to bebeam steerable so that multiple different antenna beam directions can beobtained from a single antenna 102 a, 102 b. Control over the requiredantenna field patterns can be facilitated by the RFID readers as notedabove. Also, two antennas are shown in FIG. 1 , but it should beunderstood that the solution is not limited in this regard. Theinventive arrangements described herein could be implemented using asingle beam steerable antenna.

The RFID portal system 100 can be placed in the vicinity of a physicalchoke point 104 in a facility where goods and items must pass through inorder to transition from one space to a second space. In the exampleshown in FIGS. 1 and 2 , the choke point 104 is a doorway, but otherscenarios are possible. In some scenarios the RFID readers 106 a, 106 bcan be operated under the command of a system controller 108 whichfacilitates the detection of one or more RFID tags 110 within a field ofview of each antenna as hereinafter described. In other scenarios thefunctional features associated with the system controller 108 asdescribed herein can be integrated with the RFID reader, in which casethere is no need for a separate system controller 108.

As shown in FIG. 3 , the RFID portal system 100 will define a boundary304 which separates a portal zone 300 into a first space 301 and asecond space 302. The portal zone generally defines the area in whichthe RFID portal system 100 is capable of detecting and reading RFIDtags. The portal zone is shown as a regular rectangular shape in FIG. 3, but it should be understood that the actual shape of the zone can besomewhat irregular, as it will depend on the portal reader, antennasystem and environmental factors which defines the field of view of thesystem. The first space and the second space are respectively physicalspaces or areas of the portal zone defined on opposing sides of theboundary as shown. The RFID portal system in a solution described hereinwill (1) inventory all tags crossing the portal between the first andsecond space, (2) provide enough reads per crossing tag to determinedirectionality of such movement. In some scenarios, the RFID portalsystem can also (3) inventory all static tags in the portal zonesurrounding the portal.

In a solution disclosed herein an RFID portal system 100 is configuredto detect a direction of travel with respect to RFID tags that arepassing between the first space 301 and the second space 302. Thesetypes of RFID portal systems are known in the art and therefore will notbe described here in detail. However, it should be understood thatvarious techniques can be applied to extract such directionalinformation from a series of RFID tag reads, and any RFID portal systemthat is capable of such directional detection can be used for thispurpose.

For example, it is known, that tag directionality can be determined bythe order in which tags are read. In such scenarios, an RFID portalsystem can read a tag using two separate antennas which are spaced adistance apart. In such scenarios an RFID tag that is read by a firstantenna and then by a second antenna at a later time, is likely movingfrom the first antenna to the second antenna. More advanced systems usebeam steerable antennas to detect the presence of RFID tags in differentlocations as they move through a portal zone. One example of a systemfor determining tag directionality is disclosed in U.S. Pat. No.9,519,811 to Simon, et al., the entirety of which is incorporated hereinby reference.

As shown in FIGS. 4 and 5 , a secured area 400, 500 can have one or moreRFID portal system 100 ₁ . . . 100 _(n) (where n is some integernumber), each of which may be placed in the vicinity of a physical chokepoints 104 ₁, 104 ₂, 104 ₃, . . . 104 _(m) (where m is an integer). Eachof the RFID portal systems is aligned with a boundary 504 which can beunderstood to separate the secured areas 400, 500 from unsecured areas.The physical choke points may define a location of a facility wherepersons, goods and/or items must pass through in order to transitionfrom one space (e.g., secured area 400) to a second space (unsecuredspace) exclusive of the first space. Each of the choke points 104 ₁, 104₂, 104 ₃, . . . 104 _(m) can be associated with a doorway, but thesolution is not limited in this regard and other scenarios are possible.Each RFID detection system 100 ₁-100 _(n) can be similar to the RFIDdetection system described herein with respect to FIGS. 1-3 .

In a scenario shown in FIG. 4 , the RFID portal systems 100 ₁-100 _(n)can each communicate with a RFID system server 402 to coordinate RFIDoperations. The RFID system server 402 and a data store 406 to which ithas access can be located at the secured facility 400. However, in somescenarios one or both of these components can be situated at a locationthat is remote from the secured facility. Communications with the RFIDserver 402 can be facilitated by means of a plurality of communicationlinks 404 ₁-404 _(n). In an alternative scenario shown in FIG. 5 , theRFID portal systems 100 ₁-100 _(n) can communicate directly with otherRFID portal systems 100 ₁-100 _(n) to coordinate RFID operations. Forexample, such communications can be facilitated by means of a pluralityof communication links 504 ₁-504 _(n).

Communication links 404 ₁-404 _(n), 504 ₁-504 _(n) can be comprised ofany suitable type of wired or wireless communication link. In somescenarios, the communication links 404 ₁-404 _(n), 504 ₁-504 _(n) can becomprised of a local area network utilizing a conventional well knownwired or wireless LAN standard, such as Ethernet or IEEE 802.11. Ofcourse the solution is not limited in this regard and any other suitablelink layer communication standard can be used to implement suchcommunications. In some scenarios, the communications links can beimplemented using a suitable application layer communication protocol,such as the well-known Message Queuing Telemetry Transport (MQTT) tofacilitate such communications. Still, the solution is not limited inthis regard and other types of application layer protocols can also beused for this purpose.

The operation of a system as shown in FIGS. 1-5 is described below infurther detail in relation to the flowcharts which are shown in FIGS. 6Aand 6B. The process begins at 602 and continues at 604 where one or moreRFID portal systems (e.g., RFID portal system(s) 100), each defining aportal zone (e.g., a portal zone 300), are used to detect tag dataassociated with one or more RFID tags which enter or exit a secured area(e.g., a secured area 400, 500). In some scenarios, the tag data whichis read from each tag can comprise an Electronic Product Code or EPCassociated with the particular RFID tag which has been read. For eachtag passing through the portal zone of one of the RFID portal systems, atag direction is evaluated at 606. This evaluation is configured todetermine whether the tag is entering or leaving the secured area (e.g.,secured area 400, 500). This evaluation can be performed by a systemcontroller 108 or by certain logic circuitry associated with the RFIDreader 106 a, 106 b.

If the RFID tag is entering the secured area (608: Yes) from theexternal unsecured environment, then it is considered a foreign tag andit can be inferred that the tag should not trigger an alarm when the tagexits the secured area. In such a scenario, information pertaining tothe detected tag can be added to a safe to exit (STE) list at 614. Thisinformation is sometimes referred to herein as a tag value. An exampleof an STE list 700 is shown in FIG. 7 . The STE list 700 can compriseone or more tag values 702 which are associated with those RFID tagswhich will be permitted to exit the secured facility without triggeringan alarm. The STE list can in some scenarios also include certainmetadata for each tag value. For example, the metadata can include timestamp data 704 indicating an entry time when the tag was detectedentering the secured facility. Similarly, the metadata can include otherpotentially useful information, such as portal data 706 indicating theparticular RFID portal system 104 ₁-104 _(m) where the RFID tag wasdetected as entering the secured facility.

In some scenarios the tag value that is stored in the STE list can bethe same as the data that is read from the RFID tag. For example, insome scenarios the EPC data that is read from the RFID can be stored inthe STE list without alteration. However, the solution is not limited inthis regard and in other scenarios a tag value can be directly orindirectly derived from the actual data that is read from the RFID tag.For example, the tag value can comprise a portion of the data which isread from the tag. In such a scenario if the RFID tag data is an EPCvalue, then the tag value stored in the STE list could be comprised of aselected portion of the EPC data. Alternatively, the tag value could bea value that is calculated based on the value that has been read fromthe RFID tag.

There are some circumstances when an RFID tag detected entering thesecured facility is not an appropriate candidate for inclusion on theSTE list. For example, when a facility is resupplied or stocked withmerchandise or other goods to which RFID tags are attached, such tagsshould not be included in a STE list. If the information pertaining tosuch RFID tags were added to the STE list, then a theft alarm would notbe generated when those RFID tags are detected leaving the securedfacility. To prevent such an undesirable result, a determination can bemade at 610 as to whether an RFID tag which has been detected enteringinto the secured area is detected concurrently with numerous other RFIDtags also entering the secured facility. If so, (610: Yes) then thiswill serve as an indication that the detected RFID tag is included withnew inventory which is being used to replenish the secured facility. Insuch a scenario, information concerning the detected RFID tag will notbe added to the STE list, and the process can return to 604.

In other scenarios, it can be desirable to disable the process whichinserts tag values for detected RFID tags to the STE list. Thisoperation can be performed manually and/or automatically. Disabling suchprocess (612: Yes) can be performed manually in response to a usercommand. For example, a clerk or associate at the secured facility candisable the insertion of new tag values to the STE list at a time when ashipment of new inventory is being received at the secured facility.Alternatively, the disabling process can occur automatically (e.g., atpredetermined time each week, or after normal business hours) when it isanticipated that new shipments of merchandise or other RFID tagged goodsare to be received at the secured facility. If the STE list registrationprocess has been disabled (612: Yes) then the process can return to itsRFID tag monitoring operations at 604.

If the RFID tag entering the secured facility is not detected asconcurrently entering with numerous other RFID tags (610: No), and theSTE list operations have not been disabled (612: No) then the processcan continue to 614. At 614 the system controller will perform actionsto cause a tag value corresponding to the tag data of the detectedincoming RFID tag to be added to at least one STE list which isaccessible to one or more of the RFID portal systems that are associatedwith a particular secured area. These operations can includecommunication of certain data to other devices in the system tofacilitate updating of STE lists maintained by such devices. Thecommunicated data can include one or more of tag data, tag values, atime when the RFID tag was detected entering the secured facility, andthe particular RFID portal where the tag entered the facility. Thesecommunication operations are discussed below in greater detail

In some scenarios, the STE list can be stored in a data store 406associated with a RFID system server 402. However, it is advantageous toensure that a complete updated copy of the STE list is stored at each ofthe RFID portal systems. For example, the STE list could be stored in amemory or data storage device (not shown in FIGS. 1-5 ) which isaccessible to the system controller 108, and/or the RFID reader 106 a,106 b). Storing a copy of the STE list at each of the RFID portalsystems is advantageous as it minimizes potential latencies caused bycommunications with servers and/or other RFID portal systems that arephysically remote. Such latencies are to be avoided when possiblebecause an RFID portal system which detects an RFID tag exiting thesecured facility must generate alarms (or determine that no alarm shouldbe generated) in real time as RFID tags are detected leaving the securedfacility.

In some scenarios, the presence of an STE list at each of the RFIDportal systems is facilitated by communicating RFID tag data and/or tagvalues to an RFID system server 402, which maintains a master STE list.For example, at 614 an RFID portal system which detects a foreign RFIDtag entering the secured facility can communicate the tag data and/ortag value to the RFID system server 402. The various RFID portal systems100 ₁-100 _(n) can then periodically communicate with the RFID systemserver 402 to request STE list updates. When updates are received fromthe central server, each of the remaining RFID portal systems 100 ₁-100_(n) can update the tag values which are contained on their respectiveSTE lists to include tag values for RFID tags detected entering thesecured facility.

In other scenarios, the presence of an STE list at each of the RFIDportal systems is facilitated by communicating RFID tag data and/or tagvalues directly among the RFID portal systems. For example, at 614 anRFID portal system 100 ₁ which detects a foreign RFID tag entering thesecured facility can communicate the tag data and/or tag value directlyor indirectly to one or more of the other RFID portal systems 100 ₂ . .. 100 _(n). This communication could be a multicast communication acrossa peer-to-peer network or could employ retransmission of the informationby other RFID portal systems participating in the network. However, thesolution is not limited in this respect and the exact nature of thecommunication network is not critical. When updates are received, eachof the RFID portal systems 100 ₁-100 _(n) can update the tag valueswhich are contained on their respective STE lists to include tag valuesfor RFID tags detected entering the secured facility.

There can be scenarios when an RFID tag value which has been added tothe STE list will subsequently need to be removed from such list. Forexample, such a scenario can arise in a retail store context where acustomer wishes to return merchandise which has been previouslypurchased. Note that when the customer arrives at the retail store(secured facility) an RFID tag attached to the returning merchandisewill be detected as it enters the store. Consequently, the tag valueassociated with the RFID tag will be stored in the STE list(s). When themerchandise return and/or exchange is completed the returned merchandisewill once again be a part of the retail store inventory. At this point,if an RFID tag attached to such merchandise is detected leaving thesecured facility without authorization, such departure should trigger atheft alarm. Accordingly, the tag value associated with such RFID tagshould no longer be included on the STE list.

A similar scenario can arise when a shipment of new merchandise has beenreceived at the secured facility. The shipment may not include asufficient quantity of RFID tags entering the store concurrently at 610such that the tag values are excluded from the STE list at 610. In otherscenarios, the excluding action initiated at 610 may be intentionallydisabled or absent from a particular system. In other scenarios, ashipment of new merchandise may enter into the secured facility at atime when the operation of the system has not been disabled at 612. Inthese and other scenarios, it can be advantageous to have the ability tocause tag values associated with certain RFID tags to be removed fromthe STE list.

Accordingly, for those scenarios when it is desirable to remove aparticular tag value from the STE list, a determination can be made at616 as to whether a user input has been received to indicate that aparticular tag value should be removed from the STE list (616: Yes). Insome scenarios, this determination can involve a user input which may befacilitated by an RFID reader 408 (e.g., a handheld RFID reader) forreading tag data from a particular RFID tag. According to one aspect,the RFID tag which is read with RFID reader 408 may be associated withmerchandise that is being returned or exchanged in a retail storesetting. The tag reading operation can be performed by a sales associatewho follows a point of sale return process. In other scenarios, the RFIDtag that is read may be associated with a shipment of new merchandisewhich has been delivered to the store.

In either case, a user can use the RFID reader 408 to read the RFIDtag(s) to determine tag data for one or more RFID tags which are to beremoved from the STE list. The RFID reader can be further configured tocommunicate with the RFID system server and/or the RFID portal systemsat 616. When such communication is received by an RFID portal systemand/or an RFID system server 402 it can comprise an indication that aparticular tag value for such RFID tag should be removed from an STElist. Such communications can be facilitated using a wired or wirelesscommunication link 410. The wired or wireless communication link can insome scenarios be compatible with network communications conducted usingcommunication links 404 ₁ . . . 404 _(n), 504 ₁ . . . 504 _(n).Thereafter, the tag value is removed from the STE list at 618. As aresult of this removal from the STE list, the particular RFID tagcorresponding to the removed tag value will trigger an alarm if it isdetected departing from the secured facility. The process can terminateat 620 or can continue with other processing. For example the processcan return to 604 where the one or more RFID portal systems willcontinue detecting tags which enter into a portal zone.

In other scenarios, the process for removing tag values from the STElist at 616 can be automated. For example a timing or time-out mechanismcan be used to facilitate such automatic removal of tag values from theSTE list after a predetermined period of time. Recall that the STE listcan in some scenarios include time stamp metadata 704 for each tagvalue, which specifies an entry time when each particular foreign RFIDtag was detected entering the secured facility at a particular portal.This time stamp data can be used as a basis to allow tag values to beautomatically removed from the STE list after a predetermined period oftime (e.g., 2 hours).

For example, the time stamp metadata associated with a particular tagvalue can be automatically compared to a current time at 616. Thecurrent time can be determined by a system clock at an RFID portalsystem 100 ₁ . . . 100 _(n) and/or RFID system server 402. Based on suchcomparison, the particular tag value can then be automatically purgedfrom the STE list if the corresponding time stamp metadata indicatesthat the tag value has been present on the STE list for a period whichexceeds some predetermined duration of time. The duration of time can bechosen to be of sufficiently long duration so that any customer whoenters the secured area with a foreign tag will most likely havedeparted from the secured facility before the tag value has been removedfrom the STE list.

If it is determined at 608 that a tag passing through a portal zone isnot in the process of entering the secured area (608: No), then theprocess continues at 622 where a determination is made as to whether thetag is departing from the secured area. If so (622: Yes), then action624 can optionally be performed to determine if the RFID tag isauthorized for removal from the secured facility. For example, suchauthorization may be based on a notification of a point-of-sale (POS)transaction indicating that the merchandise associated with a particularRFID tag has been purchased by a customer. In such scenarios (624: Yes),the departure of the tag through the portal zone should be permitted at626 without triggering any alarm.

If the RFID tag is a foreign tag, it will not be authorized fordeparture from the secured facility based on a POS transaction (624:No). Accordingly, the process will continue at 628 where actions areperformed to compare the tag value associated with that particular RFIDtag that is leaving the secured area, with tag values included in theSTE list. If there is no matching tag value contained in the STE list(630: No) then an alarm or notification will be triggered at 632. Ifthere is a matching tag value included in the STE list (630: Yes) then asystem alarm and/or notification can be disabled or prevented at 634.Once the foreign RFID tag has departed the secured area, thecorresponding tag value for such RFID tag can be automatically removedfrom the STE list at 636. Thereafter, the process can terminate at 638or can continue with additional processing operations. For example, theprocess can return to 604 to continue with the RFID tag monitoringoperations.

The systems described herein can comprise one or more components such asa processor, an application specific circuit, a programmable logicdevice, a digital signal processor, or other circuit programmed toperform the functions described herein. The system can be realized inone computer system or several interconnected computer systems. Any kindof computer system or other apparatus adapted for carrying out themethods described herein is suited.

Referring now to FIG. 8A, a system controller 108 as described hereincan include a processor 812 (such as a central processing unit (CPU)), adisk drive unit 806, a main memory 820 and a static memory 818, whichcommunicate with each other via a bus 822. In some scenarios, the systemcontroller 108 can further include a display unit 802, such as a videodisplay (e.g., a liquid crystal display or LCD), a flat panel, or asolid state display. The system controller 108 can include a user inputdevice 804 (e.g., a keyboard), a cursor control device 814 and a networkinterface device 816.

The disk drive unit 806 includes a computer-readable storage medium 810on which is stored one or more sets of instructions 808 (e.g., softwarecode) configured to implement one or more of the methodologies,procedures, or functions described herein. The instructions 808 can alsoreside, completely or at least partially, within the main memory 820,the static memory 818, and/or within the processor 812 during executionthereof by the system controller. The main memory 820 and the processor812 also can constitute machine-readable media. An STE list 700 asdescribed herein can be stored in the main memory 820 or any othersuitable memory location associated with the system controller 108

Those skilled in the art will appreciate that the system controllerarchitecture illustrated in FIG. 8A is one possible example of a systemcontroller. However, the invention is not limited in this regard and anyother suitable system controller architecture can also be used withoutlimitation. Dedicated hardware implementations including, but notlimited to, application-specific integrated circuits, programmable logicarrays, and other hardware devices can likewise be constructed toimplement the methods described herein. Applications that can includethe apparatus and systems of various embodiments broadly include avariety of electronic and system controllers. Some embodiments mayimplement functions in two or more specific interconnected hardwaremodules or devices with related control and data signals communicatedbetween and through the modules, or as portions of anapplication-specific integrated circuit. Thus, the exemplary system isapplicable to software, firmware, and hardware implementations.

The methods described herein are stored as software programs in acomputer-readable storage medium and are configured for running on acomputer processor. Furthermore, software implementations can include,but are not limited to, distributed processing, component/objectdistributed processing, parallel processing, virtual machine processing,which can also be constructed to implement the methods described herein.In the various embodiments of the present invention a network interfacedevice 816 connected to a network environment communicates over thenetwork using the instructions 808.

While the computer-readable storage medium 810 is shown to be a singlestorage medium, the term “computer-readable storage medium” should betaken to include a single medium or multiple media (e.g., a centralizedor distributed database, and/or associated caches and servers) thatstore the one or more sets of instructions. The term “computer-readablestorage medium” shall also be taken to include any medium that iscapable of storing or encoding a set of instructions for execution bythe machine and that cause the machine to perform any one or more of themethodologies of the present disclosure.

The functional features associated with a system controller 108 canoptionally be integrated with the RFID reader. Such an RFID reader 826is illustrated in FIG. 8B, which includes one or more of a processor 812(e.g., a microprocessor or a microcontroller), a disk drive unit 806, amain memory 820 and a static memory 818, which communicate with eachother via a bus 822. In some scenarios, the RFID reader 826 can furtherinclude a display unit 802, such as a video display (e.g., a liquidcrystal display or LCD), a flat panel, or a solid state display. TheRFID reader can include a user input device 804 (e.g., input keys and/ora keyboard), a cursor control device 814 and a network interface device816.

Further the RFID reader 826 can include one or more RF transceiver(s)818 and one or more antenna(s) 820. One or more of the RF transceiverscan also be coupled to an external antenna system, such as antennas 102a, 102 b. As such, the RFID reader 826 comprises an RF enabled devicefor allowing data to be wirelessly exchanged with one or more externaldevices (e.g., other RFID portal systems 100 ₁ . . . 100 _(n), RFIDsystem server 402, RFID handheld reader 408 and/or RFID tags 110) via RFtechnology. The RFID reader 826 is configured to transmit RF carriersignals to the listed external devices, and/or transmit data responsesignals (e.g., reply signals). Further, RFID reader 826 is capable ofreceiving RF signals including information from a transmitting device(e.g., other RFID portal systems 100 ₁ . . . 100 _(n), RFID systemserver 402, RFID handheld reader 408 and/or RFID tags 110), andforwarding such information to the processor 812 for extracting theinformation therefrom. The processor 812 can store the extractedinformation (such as the STE list 700) in memory 820, and can executealgorithms using the extracted information.

It should be understood that the RFID reader 826 can include more orfewer components than are shown in FIG. 8B. However, the componentsshown are sufficient to disclose an illustrative solution. Some or allof the components of the RFID reader 826 can be implemented in hardware,software and/or a combination of hardware and software. The hardwareincludes, but is not limited to, one or more electronic circuits. Theelectronic circuit may comprise passive components (e.g., capacitors andresistors) and active components (e.g., processors) arranged and/orprogrammed to implement the methods disclosed herein.

Referring now to FIG. 9 , there is provided a detailed block diagram ofan exemplary architecture for a handheld RFID tag reader 408. HandheldRFID tag reader 408 may include more or less components that that shownin FIG. 9 . However, the components shown are sufficient to disclose anillustrative embodiment implementing the present invention. Some or allof the components of the handheld RFID tag reader 408 can be implementedin hardware, software and/or a combination of hardware and software. Thehardware includes, but is not limited to, one or more electroniccircuits. The electronic circuit may comprise passive components (e.g.,capacitors and resistors) and active components (e.g., processors)arranged and/or programmed to implement the methods disclosed herein.

The handheld RFID tag reader 408 comprises an RF enabled device forallowing data to be exchanged with an external device (e.g., RFID portalsystems 100 ₁ . . . 100 _(n), RFID system server 402, and/or RFID tags110) via RF technology. The components 904-916 shown in FIG. 9 may becollectively referred to herein as the RF enabled device 950, andinclude a power source 912 (e.g., a battery).

The RF enabled device 950 further comprises an antenna 902 for allowingdata to be exchanged with the external device via RF technology (e.g.,RFID technology or other RF based technology). The external device maycomprise RFID portal systems 100 ₁ . . . 100 _(n), RFID system server402, and/or RFID tags 110. In this case, the antenna 902 is configuredto transmit RF carrier signals (e.g., interrogation signals) to thelisted external devices, and/or transmit data response signals (e.g.,authentication reply signals) generated by the RF enabled device 950. Inthis regard, the RF enabled device 950 comprises an RF transceiver 908.RFID transceivers are well known in the art, and therefore will not bedescribed herein. However, it should be understood that the RFtransceiver 908 receives RF signals including information from thetransmitting device, and forwards the same to a logic controller 910 forextracting the information therefrom. The logic controller 910 can storethe extracted information in memory 904, and execute algorithms usingthe extracted information.

Memory 904 may be a volatile memory and/or a non-volatile memory. Forexample, the memory 904 can include, but is not limited to, a RandomAccess Memory (“RAM”), a Dynamic Random Access Memory (“DRAM”), a StaticRandom Access Memory (“SRAM”), a Read-Only Memory (“ROM”) and a flashmemory. The memory 904 may also comprise unsecure memory and/or securememory. The phrase “unsecure memory”, as used herein, refers to memoryconfigured to store data in a plain text form. The phrase “securememory”, as used herein, refers to memory configured to store data in anencrypted form and/or memory having or being disposed in a secure ortamper-proof enclosure.

Instructions 922 are stored in memory for execution by the RF enableddevice 950 and that cause the RF enabled device 950 to perform any oneor more of the methodologies of the present disclosure. The instructions922 are generally operative to facilitate RFID tag reading operationsand communication of certain data to RFID portal devices and/or RFIDsystem server using a communications interface 918.

Referring now to FIG. 10 , there is provided a detailed block diagram ofan exemplary architecture for an RFID system server 402. Notably, theRFID system server 402 may include more or less components than thoseshown in FIG. 10 . However, the components shown are sufficient todisclose an illustrative embodiment implementing the present invention.The hardware architecture of FIG. 10 represents one embodiment of arepresentative RFID system server configured to facilitate the provisionof an STE list as described herein. Some or all the components of theRFID system server 402 can be implemented as hardware, software and/or acombination of hardware and software. The hardware includes, but is notlimited to, one or more electronic circuits. The electronic circuits caninclude, but are not limited to, passive components (e.g., resistors andcapacitors) and/or active components (e.g., amplifiers and/ormicroprocessors). The passive and/or active components can be adaptedto, arranged to and/or programmed to perform one or more of themethodologies, procedures, or functions described herein.

As shown in FIG. 10 , the RFID system server 402 comprises a userinterface 1002, a Central Processing Unit (“CPU”) 1006, a system bus1010, a memory 1012 connected to and accessible by other portions ofRFID system server 402 through system bus 1010, and hardware entities1014 connected to system bus 1010. The user interface can include inputdevices (e.g., a keypad 1050) and output devices (e.g., speaker 1052, adisplay 1054, and/or light emitting diodes 1056), which facilitateuser-software interactions for controlling operations of the RFID systemserver 402.

At least some of the hardware entities 1014 perform actions involvingaccess to and use of memory 1012, which can be a Random Access Memory(“RAM”), a disk driver and/or a Compact Disc Read Only Memory(“CD-ROM”). Hardware entities 1014 can include a disk drive unit 1016comprising a computer-readable storage medium 1018 on which is storedone or more sets of instructions 1020 (e.g., software code) configuredto implement one or more of the methodologies, procedures, or functionsdescribed herein. The instructions 1020 can also reside, completely orat least partially, within the memory 1012 and/or within the CPU 1006during execution thereof by the RFID system server 402. The memory 1012and the CPU 1006 also can constitute machine-readable media. The term“machine-readable media”, as used here, refers to a single medium ormultiple media (e.g., a centralized or distributed database, and/orassociated caches and servers) that store the one or more sets ofinstructions 1020. The term “machine-readable media”, as used here, alsorefers to any medium that is capable of storing, encoding or carrying aset of instructions 1020 for execution by the RFID system server 402 andthat cause the RFID system server 402 to perform any one or more of themethodologies of the present disclosure.

In some embodiments of the present invention, the hardware entities 1014include an electronic circuit (e.g., a processor) programmed forfacilitating the distribution and maintenance of an STE list to one ormore RFID portal systems. In this regard, it should be understood thatthe electronic circuit can access and run a foreign RFID tag managementsoftware application 1024 installed on the RFID system server 402. Thesoftware application 1024 is generally operative to facilitate: addingand/or deleting tag values from one or more STE lists maintained by theserver and/or RFID portal systems, determination of tag values based ontag data provided by the RFID portal systems, communicating certain datato and from RFID portal systems, and determining when RFID tag valuesshould be added or removed from the STE list. In some scenarios, theRFID system server 402 can also facilitate communications with a pointof sale server system (or may itself comprise a point of sale serversystem) which identifies tag values associated with RFID tags that areauthorized to depart from a secured area. If the server performs POSfunctions, it can further include a POS application software 1026 whichalso executes on the server.

Although the systems and methods have been illustrated and describedwith respect to one or more implementations, equivalent alterations andmodifications will occur to others skilled in the art upon the readingand understanding of this specification and the annexed drawings. Inaddition, while a particular feature may have been disclosed withrespect to only one of several implementations, such feature may becombined with one or more other features of the other implementations asmay be desired and advantageous for any given or particular application.Thus, the breadth and scope of the disclosure herein should not belimited by any of the above descriptions. Rather, the scope of theinvention should be defined in accordance with the following claims andtheir equivalents.

We claim:
 1. A method for managing RFID tags, comprising: using a firstRFID portal system to read tag data from an RFID tag present within afirst portal zone; using at least one processing device associated withthe first RFID portal system to determine whether the RFID tag isentering an area, the determination based on an evaluation of a movementof the RFID tag through the first portal zone; responsive to adetermination that the RFID tag is entering the area, performing atleast one operation to cause a first tag value corresponding to the tagdata to be added into a list maintained in a memory device accessible tothe at least one processing device, wherein the list specifies one ormore RFID tags which are allowed to transition out of the area withouttriggering a notification; and preventing the first tag value from beingadded to the list when the at least one processing device determinesthat the RFID tag has entered the area concurrent with a number of otherRFID tags.
 2. The method according to claim 1, further comprising: usinga second RFID portal system to read a departing tag data from adeparting RFID tag that is exiting the area; and preventing the secondRFID portal system from generating a second notification if a second tagvalue associated with the departing tag data matches at least one tagvalue stored in the list.
 3. The method according to claim 2, whereinthe second RFID portal system is the first RFID portal system.
 4. Themethod according to claim 2, wherein the second RFID portal system isdistinct from the first RFID portal system.
 5. The method according toclaim 4, further comprising communicating the first tag value to acentral server in communication with the first RFID portal system andthe second RFID portal system.
 6. The method according to claim 4,further comprising communicating the first tag value to at least thesecond RFID portal system.
 7. The method according to claim 4, furthercomprising maintaining the list at both the first RFID portal system andthe second RFID portal system.
 8. The method according to claim 1,further comprising removing the first tag value from the list responsiveto at least one manual user control operation.
 9. The method accordingto claim 1, further comprising removing the first tag value from thelist after a duration of time.
 10. The method according to claim 1,wherein preventing the first tag value from being added to the listcomprises preventing addition to the list of one or more of tag valuesduring at least one period of time.
 11. An RFID portal system formanaging RFID tags, comprising: a first RFID portal comprising a firstRFID reader including a control unit which is configured to: generateone or more commands to cause the first RFID reader to read tag datafrom an RFID tag present within a first portal zone; determine, based onan evaluation of a movement of the RFID tag through the first portalzone, whether the RFID tag is entering an area; and responsive to adetermination that the RFID tag is entering the area, perform at leastone operation to cause a first tag value corresponding to the tag datato be added into a list maintained in at least one memory device,wherein the list specifies one or more RFID tags which are allowed totransition out of the area without triggering a notification; andprevent the first tag value from being added to the list upon adetermination that the RFID tag has entered the area concurrent with anumber of other RFID tags.
 12. The RFID portal system according to claim11 further comprising: a second RFID portal comprising: a second RFIDreader including a second control unit configured to generate one ormore commands to cause the second RFID reader to: read a departing tagdata from a departing RFID tag that is exiting the area; and prevent asecond system controller from generating a second notification if asecond tag value associated with the departing tag data matches at leastone tag value in the list.
 13. The RFID portal system according to claim12, wherein the second RFID portal is the first RFID portal.
 14. TheRFID portal system according to claim 12, wherein the second RFID portalis distinct from the first RFID portal.
 15. The RFID portal systemaccording to claim 14, further comprising a central server which isconfigured to facilitate distribution of information concerning contentof the list from the first RFID portal to at least the second RFIDportal.
 16. The RFID portal system according to claim 14, wherein thefirst RFID reader is configured to directly communicate the first tagvalue to at least the second RFID reader.
 17. The RFID portal systemaccording to claim 14, wherein each of the first RFID reader and thesecond RFID reader is configured to maintain a local copy of the listrespectively in a first local data storage device and a second localdata storage device.
 18. The RFID portal system according to claim 11,wherein the first RFID reader is configured to remove the first tagvalue from the list responsive to at least one manual user controloperation.
 19. The RFID portal system according to claim 11, wherein thefirst RFID reader is configured to remove the first tag value from thelist after a duration of time.
 20. The RFID portal system according toclaim 11, wherein to prevent the first tag value from being added to thelist, the first RFID reader is configured to prevent addition to thelist of one or more of tag values during at least one period of time.